If you want proof of the utility of wetlands in a flood, look no further than Longmont, Colorado. The massive flooding there has washed out roads, flooded basements, and made lakes out of farm fields. I was watching footage from a helicopter survey of the flooding when I noticed the scene above. The dry-looking green section to the right of the homes is a wetland, they told me. The homes next to it, while a bit higher in elevation, look to be doing just fine.